Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
  • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
  • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
  • B42D25/40—Manufacture
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
  • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
  • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
  • B42D25/30—Identification or security features, e.g. for preventing forgery
  • B42D25/324—Reliefs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
  • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
  • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
  • B42D25/20—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof characterised by a particular use or purpose
  • B42D25/29—Securities; Bank notes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
  • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
  • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
  • B42D25/30—Identification or security features, e.g. for preventing forgery
  • B42D25/328—Diffraction gratings; Holograms
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
  • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
  • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
  • B42D25/30—Identification or security features, e.g. for preventing forgery
  • B42D25/342—Moiré effects
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
  • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
  • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
  • B42D25/30—Identification or security features, e.g. for preventing forgery
  • B42D25/351—Translucent or partly translucent parts, e.g. windows
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B3/00—Simple or compound lenses
  • G02B3/02—Simple or compound lenses with non-spherical faces
  • G02B3/08—Simple or compound lenses with non-spherical faces with discontinuous faces, e.g. Fresnel lens
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B5/00—Optical elements other than lenses
  • G02B5/18—Diffraction gratings

Definitions

• the present invention relates to an assembly consisting, on the one hand, of a complex transparency device, that is to say of a refractive and / or diffractive device acting on the phase of light and, on the other hand, , at least one network of micro-images.
• the holographic type technique is the oldest.
• the holograms on smart card are still used, as described for example in WO9740464.
• EP281 1470 They are based on a coupling between a phase grating (such as micro-optical devices) and a network of micro-images of different pitch.
• the present invention which is based on the multiscopic type technique, aims to propose a new variant that is even more difficult to reproduce and that includes particularly effective means for verifying the authenticity of the document concerned.
• the present invention relates to an assembly consisting, on the one hand, of a complex transparency device, that is to say of a refractive and / or diffractive device acting on the phase of light and, on the other hand, part of at least one micro-image network, in which:
• said complex transparency device consists of a periodic two-dimensional network formed of individual "pupils" in which each pupil comprises a micro-optical device, at least a part of these micro-optical devices having a non-centered optical axis, and at least a part of these micro-optical devices being positioned non-periodically, that is to say with variable offsets of their optical axis within said network;
• micro-image network consists of as many micro-images as micro-optical devices
• each micro-image has a contour identical to that of the associated pupil and a surface at most identical to that of the associated pupil;
• each micro-image is subdivided into at least one image, so that when said transparency device is positioned opposite said micro-image network, and an observer observes said network through said transparency device, it sees, at least according to a given viewing direction, an image reconstituted by the combination of the thumbnails associated with this direction,
• thumbnails - that is to say only a part of these, which constitute a "first group” - are distributed in such a way that when said transparency device is positioned facing said array of micro-images, these images are each arranged along the optical axis of said associated optical micro device.
• each of said micro-optical devices has a non-centered optical axis and that all said micro-optical devices are positioned non-periodically;
• said pupils are of identical shape and surface
• micro-optical devices having a non-centered optical axis consist of Fresnel lenses
• micro-optical devices having a non-centered optical axis consist of circular blazed networks
• each micro-image is subdivided into at least two thumbnails
• said complex transparency device and said micro-image array are carried by different supports;
• said two-dimensional network of micro-images is generated by a display device such as a digital tool screen, nomadic or not.
• the invention also relates to a security document, such as a banknote, one of the opposite faces carries a complex transparency device of the set according to one of the preceding characteristics.
• said complex transparency device extends over an impression carried by one of said opposite faces, this impression constituting the two-dimensional array of micro-images of said set according to one of the preceding characteristics.
• said complex transparency device extends through a window which opens onto said opposite faces and which comprises an impression constituting the two-dimensional array of micro-images of said set according to one of the preceding characteristics, this window and this impression being arranged relative to one another so as to be superimposed at least momentarily.
• said printing consists of at least one ink chosen from the group consisting of the following inks: visible black ink, colored, matte, glossy, iridescent, metallic, optically variable, invisible but visible under ultraviolet radiation (fluorescence or phosphorescence) or visible under infrared radiation.
• - Said transparency device is coated with a transparent varnish layer, so that the upper surface of said device is flat.
• FIG. 1 is a diagram intended to illustrate the principle of multiscopia
• FIGS. 2 and 3 are diagrams intended to illustrate cases of auto-stereoscopy
• FIG. 4 is a diagram for explaining how different images are reconstructed from micro-images that extend under a lens array
• FIG. 5 is a diagram showing the equivalence between the combination of a refractive lens and a prism on the one hand, and a Fresnel lens whose optical axis is off-center on the other hand;
• FIGS. 6A to 6D are diagrams intended to show the symmetry of the mechanisms involved, namely the decentering of the optical axis of the lenses and the adaptation of the location of the image (image portion);
• FIGS. 7A to 7C illustrate a particular embodiment of the assembly according to the invention
• FIGS. 8 and 9 are top views of two variant embodiments of micro-lens array portions
• FIG. 10 is a diagram showing a banknote seen from above, and one of the faces carries an assembly according to the present invention
• FIG. 11 A is a very schematic view, in section, of the assembly of the previous figure
• FIGS. 11B and 11C are views similar to FIG. 11A of alternative embodiments
• FIG. 12 is a view similar to FIG. 10, the bill being provided with a transparent window which carries only a lens array of said set, this figure also presenting a telephone on the screen of which a microphone network can be displayed; -images;
• Figure 13 shows a ticket which comprises, in a first region, a transparent window which carries only a lens array of said set and, in a second region, an impression of a network of micro-images.
• a set consisting of two main elements, namely a complex transparency device which is likely to appear on a security document such as a banknote and which operates in transmission. , consisting of micro-optical devices, and a support on which is positioned facing the complex transparency device, with a simple alignment.
• this support accommodates, at the point where the complex transparency device is superimposed, patterns that can not be interpreted by the naked eye and that can be affixed directly to the support substrate (made of paper and / or polymer) or be visible on the screen of a phone type "smartphone" or a touch pad, for example, and be readable in reflection or transmission.
• some of the patterns may be on the support substrate and another on the nomadic device described above.
• Decryption is therefore implemented and is due to the combination of two plans, that of a network of micro-images and that of a network of micro-optical devices which are encrypted or coded individually, that is to say which means that the arrangement of the smallest constituent units, the micro-images reciprocally the micro-optics, does not follow any rule of symmetry or replication (translation), which is immediately easy to recognize by simple observation to the eye naked or helped (magnifying glass, microscope).
• the combination of the two planes can be fixed and realized once and for all either directly on the substrate of the support or indirectly via another vector itself affixed or integrated into the support substrate (for example transferred elements or hot or cold rolled, partially embedded wires, etc.).
• the system of the assembly according to the invention lies in the coding (encryption) combined support + complex transparency device.
• complex transparency device is meant any refractive device, diffractive or combined, acting on the phase of the light (for example diffractive gratings, lenses, prisms, etc.).
• Each image of the support consists of "thumbnails” corresponding to sub-elements of a network of micro-images (at the limit, the smallest image is the pixel of the image itself).
• the principle of multiscopia is to present to the vision different images according to the inclination and the orientation of the gaze.
• the best known are the use of parallax barriers or lenticular networks.
• the present invention is inspired here by generalizing it.
• the assembly according to the invention consists of a refractive two-dimensional network behind which is placed an array of micro images, each image being able to be shifted with respect to the optical axis of the lens which is directly facing it. for independent image formation purposes.
• Micro-optical device it is formed of a device whose size can vary between 25 pm and 100 pm. Its focal length may vary between 10 and 400 ⁇ m and preferably between 40 ⁇ m and 100 ⁇ m.
• Micro-image network It is formed of thumbnails whose size is greater than 2 ⁇ m and which are magnified by micro-optical devices. This allows to form a large image.
• Image the image is what is perceived when we look through a network of micro-optical devices. Its size corresponds to the size of said network, that is to say between a few square millimeters and a few square centimeters. It is formed of a set of thumbnails (otherwise called image portions).
• Thumbnail or portion of image a thumbnail is the smallest sub-element of the micro-image network and will form an image. Its size is less than or equal to that of a micro-optical device. This makes it possible to have several possible thumbnails for a given device. Thus, the thumbnail selected by a micro-optics will be different depending on the angle of view, which will create a different image. Between two consecutive images, the angle of view may vary by a few degrees.
• the first principle implemented is based on three distinct elements.
• the second is based on the design of the micro-image network. These are arranged and designed so that their facing with the optical element creates, at certain positions of the gaze, different images.
• phase folding allows to merge the imaging function with the prism function by transforming it into a translation function of the axis of the imaging object with respect to the optics. This refolding simplifies the manufacture of optics and the implementation of the second element.
• the second principle ie that the network of micro-optical devices is not necessarily periodic, makes it more difficult to copy the network if it is not covered by a compensation layer, such as as a varnish to make the surface of the network inaccessible. If this layer of compensation is not present, thanks to the invention, the arrangement of the smallest constituent units of the latter can not be deduced by simple observation.
• the device making it possible to reconstruct various images at a number of positions of the gaze resulting in a configuration of micro-optics and associated thumbnails is therefore randomly mixed, which supposes a recalculation of the resulting deviations of this stirring to maintain the conditions of the initial imaging.
• this mixing is performed with a maximum deviation constraint limited by the manufacturing constraint during the calculation of the phase mask.
• the limit is reached when the phase difference between two consecutive pixels of the edge of the mask (ie the greatest spatial frequency) is greater than rTT. Beyond that, we are under-sampled.
• Figure 1 illustrates the principle of multiscopia.
• a convergent lens LC so that we can see different images for different angles of view.
• AV1 For the viewing angle AV1, only the image portion PU is seen, since the converging lens concentrates the rays.
• AV2 For the angle of view AV2, only the image portion PI2 will be seen. We can thus have an alternation between different images.
• Figures 2 and 3 illustrate cases of use of auto-stereoscopy.
• a lenticular network RL which, as explained above, makes it possible to favor some viewing angles AV1 and AV2, so that will be visible a thumbnail portion IG for each eye. In these conditions, one will have the impression to see an image in relief.
• BP parallax barriers may be used which block portions of beams so that each eye can see different IG-images.
• a network of micro-images MI1 to MI4 is in the central position.
• Each lens of the lens array RL is delimited by a square under which four micro-images extend which are arranged such that they reconstruct a large image GI1 to GI4 for four given viewing angles AV1 to AV4.
• an axicon associated with a prism is also equivalent to an off-center circular blazed network (in English "axicon phase hologram").
• FIGS. 6A to 6D show both the effect of the decentration of the optical axis of a lens and the adaptation of the image (or image portion) in order to see whether or not the latter through the lens according to the desired angle of view.
• the image portion PI is perceived for the viewing angle AV1 when the lens is centered.
• FIG. 7A shows a complex transparency device which consists of a periodic two-dimensional network RPU formed of individual "pupils" PU, that is to say of locations here of square shape, in which each pupil PU has a micro-optical device.
• RPU periodic two-dimensional network
• each pupil PU has a micro-optical device.
• the contour of each pupil PU is shown here, but in reality it is not visible.
• this figure only shows the optical center 10 of lenses 1 placed on this network. It can be seen that these lenses have variable offsets of their optical center within the network.
• FIG. 7B the aforementioned network RPU still appears, but only micro-images 2 are now represented, with certain images 20 represented by a black square. These thumbnails are only a part of all the thumbnails and constitute a "first group". Note that their distribution is also non-periodic. However, the position of some of them coincides with those of the optical centers identified in FIG. 7A.
• FIG. 7C represents the "final situation", that is to say the one in which the two networks are superimposed.
• thumbnails are far from the center of the lenses.
• these images (different from those of the "first group” above) constitute a “second group” of images.
• Figures 8 and 9 show two microlens arrays 1 that were generated independently of one another and randomly. For each of the microlenses, the micro-images placed below are adapted accordingly. Despite the difference between the two networks, we can create a combination of lens-image arrangements such that we obtain exactly the same visual effect (for example, a growing square).
• the non-regular distribution of the lenses prevents reproduction other than by copying the particular arrangement, this arrangement being able to vary to infinity.
• This symbol may be, for example, a second image only observable according to a given angle (and therefore hidden for all other angles of observation) or an observable pattern in reflection on the surface of the lenses and related to their arrangement.
• It may be for example a finite set of lenses whose optical axis is shifted in an orderly manner in the non-periodic network to form characters or patterns. The observation of these lenses at a given angle (rather large not to see the thumbnails) would recognize the characters or patterns.
• the assembly E of the present invention is carried by a security document such as a banknote.
• Such a note 3 has been shown very schematically in FIG. 10. On one of its opposite faces, it carries said set E. As more specifically shown in the embodiment of FIG. 11, the set E consists here of a lens array 1 and a network of micro-images 2 carried by the face 30 of the bill.
• the set E can be made in this case in two stages, not necessarily consecutive, directly on the substrate of the ticket 3.
• the assembly E may also be an attached element become integral with the ticket 3 after an application step (for example in the form of a hot or cold transfer film, a hot rolled film or cold, etc.. ) or integration, as shown in Figure 11 B which shows in section a security wire carrying the set E, thread inserted into the mass of the substrate but with windows (in English "Windows") to observe it to nude on the surface in some places).
• an application step for example in the form of a hot or cold transfer film, a hot rolled film or cold, etc..
• Integration as shown in Figure 11 B which shows in section a security wire carrying the set E, thread inserted into the mass of the substrate but with windows (in English "Windows") to observe it to nude on the surface in some places).
• the assembly E may pass through the substrate (as shown in FIG. 11 C) constituting the ticket 3 (if it consists for example of a transparent polymer opacified in certain places, except for the network 1).
• micro-image network 2 it is then constituted by the recognizable result of any technique making it possible to constitute, in the form of images, forms, patterns, information, for example and without this being limiting by printing, metallization / demetallization, laser engraving.
• the latter is carried out according to any known method for applying at least one ink selected from the group consisting of the following inks: visible black ink, colored, matte, glossy, iridescent effect , metallic, optically variable, invisible but visible under ultraviolet radiation (fluorescence or phosphorescence) or visible under infrared radiation.
• the lens array 1 extends over the print, either permanently or momentarily.
• This lens array may for example be etched in a first step in a photoresist such as S1813 resin (Shipley supplier) by photolithography.
• a photoresist such as S1813 resin (Shipley supplier) by photolithography.
• a resin layer is deposited on a glass substrate.
• the resin plate is then exposed to a laser beam in the UV, which is modulated by a mask corresponding to the phase mask to be etched. After the areas of the mask that have been exposed are removed (in the case of a "positive" resin, otherwise the non-insolated parts are removed). This is how the plate is engraved in relief, the maximum engraving depth increases with the insolation time.
• lens network 1 is removable and not secured to the ticket 3 and, in this case alone, the network 2 is permanently supported by the ticket.
• the non-planar upper face of the lens array is coated with a transparent varnish, so as to make it flat and avoid any fraudulent attempt to reproduce by direct impression.
• the network is applied to the printing implemented previously.
• the ticket 3 comprises a window 4.
• This window is integral with the remainder of the note in the case of a transparent substrate (for example a ticket based on bi-oriented polypropylene).
• a transparent substrate for example a ticket based on bi-oriented polypropylene
• this window is constituted by an opening closed by a transparent polymer material, the latter accommodating the lens array 1.
• the network of micro images it can be displayed on the screen 50 of a phone 5 of the "smartphone” type or on the digital display screen of a digital tool, mobile or not.
• the networks 1 and 2 are arranged in two different regions of the ticket 3, so that by folding this ticket as shown by the arrow f, the two networks can be superposed to reveal a piece of information. or a visual effect, recognizable.
• a ticket such as that of FIG. 12, in which the window bears, in addition to the lens array, only a part (for example half) of the micro-array. images, while the complementary part is displayed on the screen of a phone or other.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Business, Economics & Management (AREA)
• Accounting & Taxation (AREA)
• Finance (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Diffracting Gratings Or Hologram Optical Elements (AREA)
• Credit Cards Or The Like (AREA)
• Printing Methods (AREA)

Priority Applications (8)

Applications Claiming Priority (2)

Publications (1)

Family

ID=62455549

Family Applications (1)

Country Status (9)

Citations (11)

Family Cites Families (18)

• 2017
  • 2017-12-14 FR FR1762169A patent/FR3075095B1/fr active Active
• 2018
  • 2018-12-13 KR KR1020207019939A patent/KR102610706B1/ko active IP Right Grant
  • 2018-12-13 JP JP2020552121A patent/JP7438963B2/ja active Active
  • 2018-12-13 UA UAA202003821A patent/UA127684C2/uk unknown
  • 2018-12-13 CN CN201880080904.6A patent/CN111867850B/zh active Active
  • 2018-12-13 WO PCT/EP2018/084669 patent/WO2019115664A1/fr unknown
  • 2018-12-13 EP EP18815717.6A patent/EP3723995B1/fr active Active
  • 2018-12-13 CA CA3085670A patent/CA3085670A1/fr active Pending
  • 2018-12-13 US US16/772,332 patent/US11148456B2/en active Active

Patent Citations (11)

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